ABSTRACT
Structuralism was formulated in the early years of the 20th century. The Gestalt theorists took a view that was opposed to structuralism, holding that the natural units of perception were forms and shapes rather than any more fundamental class of sensations. The Gestalt psychologists provided good descriptions of some examples of the perception of form, and many of their demonstrations were very convincing, but their explanations were much less useful. Identifying objects may begin with feature analysis but it also employs top-down processing, which makes use of our past experience and knowledge of the world around the reader. The resulting activity, described as pandemonium, is interpreted by the decision demon who must determine which of the cognitive demons is showing the most activity. Component-based theories are an extension of the computational approach and represent an attempt to deal with the problem of recognizing objects without relying on sets of features which have been arbitrarily defined.
